This invention relates to tree injectors. It is already known to inject liquids into a tree at or inside the region of the junction of the living interior of the truck and the outer dead material ie. the bark. Inside the bark is cambium tissue where radial growth of the tree trunk occurs. The outer layer of cambium tissue consists primarily of a phloem layer through which water passes downwards, the water containing food from the leaves. The cambium tissue also includes a xylem layer inside the phloem. Soil water rises up through the xylem tissue layer, carrying minerals and other material from the soil.
Trees are prone to damage from pests such as insects and fungus particularly entering through the bark. Such pests can be resisted by suitable pesticides or fungicides fed into the cambium so as to pass therein up or down the tree trunk, as required.